Was just watching Steve Marsh's video about his day trip from Penzance to Scilly, and in it he mentioned that there are rail+sail /rail+fly tickets. Looked them up and they've an interesting restriction in that there's a minimum 4 day stay.
www.brfares.com
There are up to eight flights a day each way so it would be possible to do a day trip, but this is the only defined fare (there's no single). Are there any other routes where it's not possible (from a ticketing perspective) to do a day trip, even though the timetable(s) would allow it, or even a two-day for that matter.
(Video linked below)

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There are up to eight flights a day each way so it would be possible to do a day trip, but this is the only defined fare (there's no single). Are there any other routes where it's not possible (from a ticketing perspective) to do a day trip, even though the timetable(s) would allow it, or even a two-day for that matter.
(Video linked below)